Various types of complex pediatric seating systems or upright support systems having various adjustable mechanisms are known for supporting a disabled person in specific positions. However, such systems are complex in construction and expensive to fabricate. They are usually custom-built to fit a person of a specific physiognomy, and therefore need to be replaced as that physiognomy changes. Most of these systems are adapted to specific devices, such as wheelchairs, and not adaptable for different functions such as also serving as support for conventional chairs, automobile seats, high chairs. A typical example of such system is illustrated and described in U.S. Pat. No. 3,761,126. That patent is restricted to a wheelchair wherein various component parts of the wheelchair are provided with adjustable mechanisms to adapt to the dimensions of a disabled person. These adjustable mechanisms are cumbersome and costly. They are also time consuming to adjust and secure to a disabled person on the wheelchair.
U.S. Pat. No. 4,234,228 relates to a modular articulated seating system for handicapped persons to hold a handicapped person securely in an orthopaedically required position. The seating system comprises a frame having three shells with a cushioning system secured to the shells, but molded to closely fit a specific person's body. They must be replaced when the body of the person is different. However, the shells or the seating system is adapted to be mounted on a variety of devices, such as the base of a wheelchair, carseat, etc. The present invention relates more generally to this type of device, but of entirely different structure providing a variety of advantages not derivable from this patented structure and some of which advantages are described hereinbelow.